1. Field of the Invention
The present invention relates to an ink jet print head employing actuators, such as piezoelectric elements, intended for use on an ink jet recording apparatus that jets ink droplets for printing.
2. Description of Related Art
A prior art ink jet head disclosed in, for example, Japanese Examined Patent Publication No. Hei 6-61936 comprises: nozzles through which ink droplets are jetted; pressure chambers communicating with the nozzles, respectively, to supply a liquid to be jetted to the nozzles; actuators each comprising two types of piezoelectric elements polarized in opposite polarities and forming the side walls of the pressure chambers, and electrodes formed on the side walls to apply an electric field perpendicular to the direction of polarization to the side walls; and an ink supply for supplying ink into the pressure chambers. When a voltage is applied across the electrodes of the actuator, the piezoelectric elements forming the side walls undergo shear deformation, causing a change in the pressure in the pressure chambers, whereby ink droplets are jetted.
The actuator of this prior art ink jet print head is formed by butt-bonding two types of piezoelectric elements, cutting grooves in the butt-bonded two types of piezoelectric elements to form the side walls, and forming the electrodes on the side walls by plating.
When the piezoelectric elements of the actuator are bonded together by a thick layer of an adhesive, the electrodes are formed with an uneven thickness because the material forming the electrodes is easy to deposit on the piezoelectric elements made of a ceramic material, but difficult to deposit on the adhesive layer made of a resin or the like and, therefore, the coverage of the films forming the electrodes is reduced. Consequently, the ability of the actuator is reduced, the jet velocity of the ink droplets is reduced, or the electrode extending across the two types of piezoelectric elements is disconnected to make ink jetting operation impossible.